PREVENTIVE MEDICINE 281 



degree of immunity is not definitely known. Immunity probably 

 does develop, but is not serviceable for any considerable time. 



PREVENTIVE MEASURES. If influenza appears in a town notice 

 of the fact should be made in the public press by the local authority 

 in order that horse-keepers may take precautionary measures. 

 Such measures are, closing the stable and stable yard to strange 

 horses or, if any must enter the yard, at least forbidding them 

 the use of the yard-trough. Carters should be supplied with pails 

 from which horses should be watered both when at work and in 

 the stable. The use of sponges and cloths should be prohibited, 

 and brushes and other grooming tools must be kept clean and fre- 

 quently soaked in disinfectant. 



If the disease appears in a stud the temperatures of all horses 

 should be taken every morning before they leave for work. This 

 is a very important precaution as it enables infected animals to be 

 detected early and removed immediately from the main stable. 



Isolation of infected animals is imperative if the spread of the 

 disease is to be prevented, and stalls that have harboured sick 

 animals must be thoroughly disinfected and left vacant for as long 

 as possible. It is important that all the litter, whether soiled or 

 not, be removed ; partially soiled litter must not be used for neigh- 

 bouring animals on the score of economy. The virus is said to 

 live for a long time in damp, badly-ventilated stables, but soon 

 loses its virulence by exposure to fresh air and sunlight. 



CONTAGIOUS EQUINE PNEUMONIA. 



This pneumonia of the horse is characterised by a marked 

 tendency of the involved lung to undergo necrosis followed by 

 gangrene (necrotic pneumonia). It may or may not be accom- 

 panied by pleurisy. While some consider contagious equine 

 pneumonia to be a distinct disease, other observers (Lignieres, 

 Hutyra and Marek) look upon it as being no more than a complica- 

 tion (pectoral form) of influenza. Miessner* describes two 

 diseases (1) Lung disease (Briistseuche) or pectoral influenza and 

 (2) Infectious bronchitis or bronchopneumonia, the latter being 

 more chronic and the alterations being primarily bronchial. The 

 direct cause is uncertain. Lignieres considers it to be a pasteurella 

 with which is often associated as a secondary invader the strepto- 

 coccus of strangles (see Influenza). Schtitz regards as the cause 

 a small ovoid bacterium which he has been able to isolate from 

 cases. Horses are the only animals affected. The disease is wide- 



* Epizootics and their Control in War, Miessner, Trans, by Liebold, 1917. 



